ANTIBACTERIAL ACTIVITY AND COMPOSITION OF ESSENTIAL OILS EXTRACTED FROM SOME PLANTS BELONGING TO FAMILY LAMIACEAE AGAINST SOME MULTIDRUG RESISTANT GRAM NEGATIVE BACTERIA

The aim of this study was to evaluate the antibacterial activity of eight essential oils against some multi-drug resistant Gram negative bacteria (three different isolates of each Acinetobacter baumannii and Klebsiella pneumoniae). The hydrodistilled essential oils of the fresh aerial part of some medicinal plants belonging to family Lamiaceae namely: Origanum majorana L. , Origanum majorana L. , Origanum syriacum L., Thymus capitatus L., Thymus vulgaris L., Salvia fruticosa Mill., Mentha virdis L. and Lavandula officinalis L. were subjected to Gas Chromatography−Mass spectrometry analysis. This revealed 25, 22, 22, 23, 23, 27, 19 and 31 compounds had been identified in the essential oils, respectively. The major components were identified as terpinen-4-ol (21.99%), terpinen-4-ol (23.56%), cymene (27.98%), carvacrol (41.55%), m-thymol (23.97%), eucalyptol (54.84%), carvone (47.79%) and eucalyptol (36.42%), respectively. Antibacterial activity was carried out and the activities were correlated to chemical composition of analyzed essential oils. We found five essential oils were the most effective. The study concluded that, some essential oils of Egyptian medicinal plants belonging to family Lamiaceae can be used to treat infections caused by multi-drug resistant gram negative bacteria. Key words: Lamiaceae, Essential oil, Hydrodistillation, Gas Chromatography−Mass spectrometry, multi-drug resistant gram negative bacteria, Antibacterial activity.